An adaptive control approach to the control of containership dynamics

AN ADAPTIVE CONTROL APPROACH TO THE CONTROL OFCONTAINERSHIP DYNAMICSFuat ALARÇİNMechanical Engineering, Ph.D. ThesisYaw and roll motion stabilization systems have crucial importance for passenger ships,military vessels and freight hauling container vessels. The container ships, in particular, havethe greatest need for motional stability. Therefore, controlling yaw and roll motion, which areparticularly apparent during sideward movement of the vessel, is of great importance forincreasing safety against hazardous situations.In this study, the stabilization of a vessel?s yaw and roll motion in order to satisfy cruisingneeds of a container ship is modeled by utilizing classic and contemporary approaches. Theyaw motion of a container ship with one and three degrees of freedom that is under the effectof wave power and moment is controlled by means of the rudder, and the rolling motion iscontrolled by utilizing the roll stabilization fins. When the results that were obtained under thegeneral approach of the thesis are examined, it is noted that motions are diminished. The fieldof application was enhanced by means of implementing yaw and roll autopilot systems intotrue container ship models, which include hydrodynamic coefficients.In order to compare the performance of control systems in consideration of the vessel?sdynamic model, the control of ship?s yaw and roll motion was conducted separately; first bydeveloping non-adaptive methods of Proportional-Integrative-Derivative (PID) and LinearQuadratic Regulator (LQR), and then the adaptive methods of Model Reference Adaptive(MRAK) and Fuzzy Logic (BM). In conclusion of the studies that were conducted up to thispoint, fuzzy logic control is recommended due to superior performance that it hasdemonstrated in controlling both yaw and roll motion.The vessels produce yaw and roll motion distinctively in comparison to others, depending onthe wave characteristics and the direction from which waves strike the vessel. Therefore,Internal Model Control (DMK) method is applied to simultaneous yaw and roll motion,rudder and roll fin control systems. A fuzzy adaptation mechanism has been developed forthis control method and Fuzzy adaptation of Internal Model Control (B-DMK) is presented asa new approach to be used on the modeled ship. The purpose here is to utilize fuzzy logic toadjust the container ship internal model control gains based on ever changing environmentalconditions in a manner that would not disrupt stability, rather than performing the control ofship way and roll motions only with internal model control or only with fuzzy logiccontrollers.The control systems that are examined in this study have been applied to a container shipmodel and the superiority of each model over one another is discussed by separatelyexamining the performance of each system. Furthermore, the performance of these adaptivecontrol systems over ship motion stabilization systems and the positive contributions thereofto traditional methods are examined.Keywords: Container ship yaw autopilot, roll stabilization systems, PID, LQR, MRAK, FLand IMC control methods.JURY:1. Ass. Prof. Dr. İsmail YÜKSEK (Supervisor) Date: 02.12.20052. Prof. Dr. Faris KAYA Page: 1893. Prof. Dr. Ahmet D. ALKAN4. Doç. Dr. Selim Sivrioğlu5. Ass. Prof. Dr. Arif ADLI